Williamson County confirms first human West Nile case of 2026

August 20, 2026

Officials with the Williamson County and Cities Health District confirmed a resident tested positive for West Nile virus on August 13. The person is in their 80s and lives in the southern portion of Williamson County, making this the county's first human case this year.

Public health agencies in the Austin area have observed an active mosquito season, with mosquito pools returning positive results in Travis, Williamson and Hays counties. Hays County announced its first human West Nile case last week, and the Centers for Disease Control and Prevention has tallied 31 cases statewide so far in 2026.

Health experts warn that while most West Nile infections cause flu like symptoms such as headache, body aches, joint pain, vomiting and diarrhea, the illness can be more dangerous for older adults and people with serious medical conditions. In severe instances the virus can affect the central nervous system.

Local health officials urged residents to protect themselves by using insect repellant, wearing long sleeves and pants outside particularly at dawn and dusk when mosquitoes are most active, and draining standing water where mosquitoes breed. Officials also noted recent weather patterns have favored mosquito reproduction, increasing transmission risk.

Williamson County health leaders are monitoring the situation and continuing surveillance of mosquito pools and human cases in the region.